Coating composition



Patented Apr. 1, 1941 COATING COMPOSITION James]. Scott and wm i am r. Barla, Fort Worth,

No Drawing. Application January 21, 1941, Serial No. 375,356

1 Claim.

This invention relates to an improved coating composition. More particularly, the invention contemplates the provision of a novel coating composition especially applicable for the coating of metal pipes such as are employed in pipe lines, well casings, and the like.

One of the greatest items of upkeep in the maintenance of pipe lines is the deterioration of the pipe line itself due to corrosion, rust, and deterioration often occasioned by the materials moving through the pipe line and also due to conditions in the soil through which the pipe line passes.

Extensive investigation has revealed that the coating composition of thepresent invention is particularly effective in preserving pipe lines against deterioration and is adapted for coating both the interior and the exterior of the pipe.

The coating composition of the instant invention possesses the capacity to metallically bond with the metal of the pipe to which it is applied in such manner that the coating becomes permanently bonded to the pipe and never scales ofl or loosens from the pipe.

The coating composition conforming to the instant invention is made up essentially in the form of an alloy. An exemplary and preferred composition of the alloy constituting the coating composition of the instant invention is as follows:

Per cent Thallium 1o Tin 20 Antimony 5 Copper 3. Lead 62 62 percent. 40

mony may then be added in the form of pigs while maintaining the temperature adequate to melt these materials. The alloy may then/be-cast .into suitable pigs, sheets, bars, or the like for.

subsequent use. The product is homogeneous and may be remelted at approximately the melting point of tin.

The coating composition is applied to the pipe in molten condition. The pipe to be coated is first cleaned; with acid, such, for example, as

muriatic acid, and the pipe is then heated to a temperature approximately that of the melting point of lead. The pipe is then introduced to a molten bath of the melted alloy until it is thoroughly and uniformly covered.

The thickness of the coating on the pipe can be closely controlled by regulating the temperature of the melted alloy. A hot mix gives a thinner coating whereas a somewhat cooler mix gives a heavier or thicker coating.

The foregoing proportions have been found to give a coating possessing especially valuable prop erties in protecting pipe lines against rust and corrosion. The hardness of the coating may be controlled by varying the amount of thallium or tin. However, it is not desired to recommend material departure from the recited proportions.

Pipe coated in accordance with this invention has stood up for prolonged periods against rust and corrosion in the handling of strong brine solutions as well as against the action of the usual corroding acids.

Having thus described the invention, what we claim is:

A coating composition comprising thallium, tin, antimony, copper, and lead inthe following proportions: thallium 10 per cent, tin 20 per cent,

antimony 5 per cent, copper 3 per cent, and lead JAMES J. SCOTI. 

